Skypea was decent for me. Not too good not too bad. In general I had nothing to complain about.
Alabasta was to me not engaging at all until the final moments of arc started.
It feels like I can skip the arc , know that SH got bounty upgrade and nothing would change.
Vivi and cobra indeed are plot points "right now" but could have judt gave us a flashback like paul.
I would say give those amount of chapters to elbaf , I would enjoy norse cultural setup more.